Spinal stabilization installation instrumentation and methods

ABSTRACT

A system for installing a vertebral stabilization system. The system includes an installation tool including a handle portion and a shaft extending distally from the handle portion. The shaft includes a conduit and a staple mechanism. The system also includes a flexible implant member extending along the conduit configured to be advanced out from a distal end of the shaft, and a staple housed in the staple mechanism. The staple is configured to secure the flexible implant member to a vertebra. The handle portion is configured to selectively advance the flexible implant member from the shaft and to selectively actuate the staple mechanism.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/872,446, filed on Apr. 29, 2013, which is a continuation of U.S.patent application Ser. No. 13/418,403, filed on Mar. 13, 2012, now U.S.Pat. No. 8,465,493, which is a continuation of U.S. patent applicationSer. No. 12/334,031, filed on Dec. 12, 2008, now U.S. Pat. No.8,137,355, the entire disclosures of which are incorporated herein byreference.

TECHNICAL FIELD

The disclosure is directed to installation instrumentation and methodsof installing a spinal stabilization system on a region of a spinalcolumn. More particularly, the disclosure is directed to an installationtool and method for advancing an elongate flexible stabilization memberbetween adjacent vertebrae and anchoring the stabilization member to theadjacent vertebrae of a spinal column.

BACKGROUND

The spinal column of a patient includes a plurality of vertebrae linkedto one another by facet joints and an intervertebral disc locatedbetween adjacent vertebrae. The facet joints and intervertebral discallow one vertebra to move relative to an adjacent vertebra, providingthe spinal column a range of motion. Diseased, degenerated, damaged, orotherwise impaired facet joints and/or intervertebral discs may causethe patient to experience pain or discomfort and/or loss of motion, thusprompting surgery to alleviate the pain and/or restore motion of thespinal column.

Methods of treating spinal column disorders include installing a spinalstabilization system to stabilize a segment of the spinal column. Oneconventional spinal stabilization system includes securing a rigid rodbetween two or more vertebrae with pedicle screws. Another techniqueutilizes a less rigid connecting element to provide a more dynamicstabilization of the affected segment of the spinal column. One exampleof a dynamic stabilization system is the DYNESYS system available fromZimmer Spine, Inc. of Minneapolis, Minn. Such dynamic stabilizationsystems may include a flexible, tubular spacer positioned betweenpedicle screws installed between adjacent vertebrae. The spacer ispositioned between the pedicle screws and a flexible cord is threadedthrough the spacer. The flexible cord is secured to the heads of thepedicle screws by set screws, thereby retaining the spacer between thepedicle screws while cooperating with the spacer to permit mobility ofthe spine.

Some such surgical techniques may be found quite invasive and timeconsuming. Thus, it is desirable to achieve dynamic stabilization of aspinal segment in a less invasive and/or less time consuming manner.Therefore, alternative systems and associated methods for installing avertebral stabilization system are desirable.

SUMMARY

The disclosure is directed to several alternative designs, materials andmethods of manufacturing medical device structures and assemblies.

Accordingly, one illustrative embodiment is an installation tool forinstalling a vertebral stabilization system. The installation toolincludes a handle portion and an elongate shaft extending distally fromthe handle portion. The elongate shaft of the installation tool includesa conduit for directing a flexible implant member to a vertebra of aspinal column and an anchoring mechanism for applying an anchor to thevertebra to secure the flexible implant member to the vertebra.

Another illustrative embodiment is a system for installing a vertebralstabilization system. The system includes an installation tool includinga handle portion and a shaft extending distally from the handle portion.The shaft includes a conduit and a staple mechanism. The system alsoincludes a flexible implant member extending along the conduitconfigured to be advanced out from a distal end of the shaft, and astaple housed in the staple mechanism. The staple is configured tosecure the flexible implant member to a vertebra. The handle portion isconfigured to selectively advance the flexible implant member from theshaft and to selectively actuate the staple mechanism.

Yet another illustrative embodiment is a medical procedure forinstalling a vertebral stabilization system. During the procedure aninstallation tool is inserted through an incision of a patient to afirst vertebra of a spinal column. The installation tool includes ahandle portion and a shaft extending from the handle portion. The shaftof the installation tool includes a conduit for directing a flexibleimplant member and an anchoring mechanism for applying an anchor. Aflexible implant member is advanced along the conduit and out from adistal end of the shaft of the installation tool. The anchoringmechanism is actuated to expel a first anchor to secure the flexibleimplant member to the first vertebra.

With the flexible implant member secured to the first vertebra, theflexible implant member is further advanced along the conduit and outfrom the distal end of the shaft of the installation tool while movingthe distal end of the shaft to a second vertebra. The anchoringmechanism is actuated to expel a second anchor to secure the flexibleimplant member to the second vertebra. An excess portion of the flexibleimplant member may then be cut away.

The above summary of some example embodiments is not intended todescribe each disclosed embodiment or every implementation of theinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may be more completely understood in consideration of thefollowing detailed description of various embodiments in connection withthe accompanying drawings, in which:

FIG. 1 is a side view of an exemplary installation tool for installing avertebral stabilization system;

FIG. 2 is an enlarged view of the distal portion of the installationtool of FIG. 1;

FIG. 3 is an enlarged view of the proximal portion of the installationtool of FIG. 1 with the switching member switched to a second position;

FIGS. 4A-4E illustrate an exemplary method of installing a vertebralstabilization system with the installation tool of FIG. 1;

FIGS. 5, 6, 7-7A, 8, 9A-9B and 10A-10B illustrate various exemplaryembodiments of an anchor which may be used with the installation tool ofFIG. 1; and

FIGS. 11A-11D illustrate various exemplary embodiments of an elongateflexible member of a vertebral stabilization system.

While the invention is amenable to various modifications and alternativeforms, specifics thereof have been shown by way of example in thedrawings and will be described in detail. It should be understood,however, that the intention is not to limit aspects of the invention tothe particular embodiments described. On the contrary, the intention isto cover all modifications, equivalents, and alternatives falling withinthe spirit and scope of the invention.

DETAILED DESCRIPTION

For the following defined terms, these definitions shall be applied,unless a different definition is given in the claims or elsewhere inthis specification.

All numeric values are herein assumed to be modified by the term“about”, whether or not explicitly indicated. The term “about” generallyrefers to a range of numbers that one of skill in the art would considerequivalent to the recited value (i.e., having the same function orresult). In many instances, the term “about” may be indicative asincluding numbers that are rounded to the nearest significant figure.

The recitation of numerical ranges by endpoints includes all numberswithin that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4,and 5).

Although some suitable dimensions ranges and/or values pertaining tovarious components, features and/or specifications are disclosed, one ofskill in the art, incited by the present disclosure, would understanddesired dimensions, ranges and/or values may deviate from thoseexpressly disclosed.

As used in this specification and the appended claims, the singularforms “a”, “an”, and “the” include plural referents unless the contentclearly dictates otherwise. As used in this specification and theappended claims, the term “or” is generally employed in its senseincluding “and/or” unless the content clearly dictates otherwise.

The use of the term “stabilization” in the present description refers tosecuring adjacent vertebrae such that the movement between the adjacentvertebrae is limited to a desired amount. Stabilization may also beachieved by not only reducing movement, but also by simply providingincreased structural integrity between adjacent vertebrae.

The following detailed description should be read with reference to thedrawings in which similar elements in different drawings are numberedthe same. The detailed description and the drawings, which are notnecessarily to scale, depict illustrative embodiments and are notintended to limit the scope of the invention. The illustrativeembodiments depicted are intended only as exemplary. Selected featuresof any illustrative embodiment may be incorporated into an additionalembodiment unless clearly stated to the contrary.

Referring now to FIG. 1, there is shown an installation tool 10configured for delivering and installing a spinal stabilization systemsuch as a dynamic stabilization system to a spinal segment. In somecircumstances, the installation tool 10 may be utilized to implant aspinal stabilization system to a vertebral segment in a percutaneous orminimally invasive manner.

The installation tool 10 may include a handle portion 12 and an elongateshaft 14 extending distally from the handle portion 12. In someembodiments, the elongate shaft 14 may extend axially along alongitudinal axis of the installation tool 10, while in otherembodiments the elongate shaft 14, or portions thereof, may be offset orotherwise deviate from the longitudinal axis of the installation tool10.

The installation tool 10 may be configured to perform one or more, or aplurality of actions in installing a vertebral stabilization system on avertebral segment of a spinal column. For instance, the installationtool 10 may advance an elongate flexible stabilization member 50 fromthe distal end 16 of the shaft 14 of the installation tool 10, maysecure one or more, or a plurality of anchors to secure the elongateflexible stabilization member 50 to vertebrae of the spinal column, maydistract adjacent vertebrae, and/or may cut away excess portions of theelongate flexible stabilization member 50.

As further shown in FIG. 2, the installation tool 10 may include aconduit 20, such as an enclosed, partially enclosed, or open conduit. Asshown in FIG. 2, the conduit 20 may be defined, at least in part, by afirst tubular member 36 of the elongate shaft 14. The conduit 20 may beconfigured to hold and direct a flexible stabilization member 50 fromthe distal end 16 of the installation tool 10. For instance, as shown inFIGS. 1 and 2, the conduit 20, through which the flexible stabilizationmember 50 extends through, may extend from a proximal portion of theshaft 14 to the distal end 16 of the shaft 14 along a longitudinal axisof the elongate shaft 14.

The elongate shaft 14 may include a ramp 22 proximate the distal end 16of the shaft 14 configured to redirect the directional movement of thestabilization member 50 upon exiting the distal opening 24 of the shaft14. For example, the ramp 22 may be an arcuate or sloped ramp extendingnon-parallel to the longitudinal axis of the shaft 14. Furthermore, insome embodiments the distal opening 24 may lie in a plane which is notperpendicular to the longitudinal axis of the shaft 14. In such anembodiment, the stabilization member 50 may be translated distally alongthe longitudinal axis of the shaft 14 until the stabilization member 50reaches the ramp 22, at which point, the ramp 22 redirects thestabilization member 50 out the distal opening 24 in a direction whichis not parallel with the longitudinal axis of the shaft 14.

Additionally or alternatively to a ramp 22, the stabilization member 50may be precurved such that as the stabilization member 50 exits thedistal opening 24 of the installation tool 10 the stabilization member50 attempts to revert to the precurved configuration. For instance, thestabilization member 50 may be held in a substantially straightconfiguration in the conduit 20 of the shaft 14, but may assume thecurved configuration when not constrained by the conduit 20. Thus, asthe stabilization member 50 exits the distal opening 24 thestabilization member 50 extends in a direction which is not parallelwith the longitudinal axis of the shaft 14. This may help position thestabilization member 50 along the vertebrae as the stabilization member50 exits the shaft 14 of the installation tool 10.

In some embodiments, the installation tool 10 may include one or morestructural features used in distracting adjacent vertebrae. For example,the installation tool 10 may include one or more, or a plurality ofprongs 26 extending from the distal end 16 of the elongate shaft 14. Theprong 26 may be configured to project or bite into a vertebrae during amedical procedure, such that medical personnel may use the installationtool 10 to distract the vertebra from an adjacent vertebra during themedical procedure.

The installation tool 10 may also include an anchoring mechanism 40,which is actuatable to expel an anchor 70 from the distal end 16 of theinstallation tool 10 to anchor the stabilization member 50 to avertebra. For instance, in some embodiments the anchoring mechanism 40may be a stapling mechanism configured to expel a staple from the distalend 16 of the installation tool 10.

The anchoring mechanism 40 may be preloaded with one or more, or aplurality of anchors 70 prior to the medical procedure. In someembodiments, the anchoring mechanism 40 may include a cartridge 44, suchas a removable cartridge, which may house a plurality of anchors 70 foruse during a medical procedure. The cartridge 44 may feed the pluralityof anchors 70, one at a time, to a driver 46 which is actuatable toexpel the anchor 70 from the installation tool 10 and drive the anchor70 into the vertebra. In some embodiments, the driver 46 may bemechanically actuated, pneumatically actuated, spring actuated, orotherwise actuated to expel an anchor 70 from the installation tool 10.In some embodiments, such as shown in FIG. 3, the driver 46 may extendalong a second tubular member 38 of the shaft 14 of the installationtool 10.

The cartridge 44 may include a feeding mechanism 48, which in someinstances, may include a spring member 52 configured to deliver theanchors 70 to and/or align the anchors 70 with the driver 46 toeffectuate expelling the anchor 70 from the distal end 16 of theinstallation tool 10.

In some embodiments, the cartridge 44 may be loaded with a plurality ofanchors 70 and then removably coupled to the elongate shaft 14 of theinstallation tool 10 prior to the medical procedure. Thus, theinstallation tool 10 may be reused in a subsequent procedure byreplacing and/or refilling the cartridge 44. In some embodiments, theinstallation tool 10 may be preloaded with a sufficient quantity ofanchors 70 to complete installation of the stabilization member 50without withdrawing the shaft 14 of the installation tool 10 from thepatient until the installation is completed. For instance, the cartridge44 may be preloaded with two, three, four, six, eight or more anchors 70prior to performing the medical procedure. In other embodiments, ananchor 70 may be fed to the anchoring mechanism 40 by the medicalpersonnel on demand as necessary.

In some embodiments, the installation tool 10 may be configured suchthat medical personnel may manually load an anchor 70 in theinstallation tool 10 from the proximal end of the installation tool 10during the medical procedure. The medical personnel may then manuallyinstall the anchor 70 into a vertebra as desired. For instance, in someembodiments an anchor 70 may be disposed in a channel formed by thesecond tubular member 38, or other channel of the installation tool 10extending from a proximal portion of the shaft 14 remaining external ofthe patient's body to the distal end 16 of the shaft 14. The channel maybe used to deliver the anchor 70 to the distal end 16 of the shaft 14 inorder to be driven into the vertebra. The medical personnel may thenmanually use a tamping device or other driver, to drive the anchor 70into the bone. Additional anchors 70 may be loaded in the channel andindividually driven into a bone by medical personnel during the medicalprocedure, as needed.

In some embodiments, the installation tool 10 may include a cutter 54which may be used to cut away an excess portion of the stabilizationmember 50 during a medical procedure. The cutter 54 may extend along theshaft 14 of the installation tool 10. In some instances, the cutter 54may have a sharpened tip 56 which may be selectively brought intocontact with the stabilization member 50 to sever a portion of thestabilization member 50 extending out of the installation tool 10 from aportion of the stabilization member 50 remaining in the conduit 20 ofthe installation tool 10. In other instances, the cutter 54 may includea plurality of jaws which may be actuated toward one another to severthe stabilization member 50 positioned between the jaws of the cutter54. It is noted that other cutting means may be utilized with theinstallation tool 10, including a separate cutting tool, to cut awayexcess portions of the stabilization member 50, if desired.

The handle portion 12 of the installation tool 10 may be used tomanipulate the installation tool 10 and/or to actuate one or morecomponents of the installation tool 10 during the medical procedure. Asshown in FIG. 1, the handle portion 12 may include a palm grip 30rigidly mounted to a base portion 18 of the shaft 14 of the installationtool 10. The palm grip 30 may be ergonomically formed to fit comfortablyin the palm of the hand of medical personnel using the installation tool10.

The handle portion 12 may also include a first trigger or actuatablehandle 32 which may be used to selectively control one or more of theoperative features of the installation tool 10. For instance, the firstactuatable handle 32 may be configured to advance the stabilizationmember 50 from the distal end 16 of the installation tool 10 when theactuatable handle 32 is actuated. For instance, the first handle 32 mayengage with a proximal portion or extension 58 the stabilization member50 to urge the stabilization member 50 distally.

The first actuatable handle 32 may be pivotably mounted to the shaft 14such that the first actuatable handle 32 may be actuated relative to thepalm grip 30. Actuation of the first actuatable handle 32 may urge tostabilization member 50 distally along the conduit 20 to advance thestabilization member 50 from the distal opening 24. The handle portion12 may include a spring 28 or other biasing means biasing the firstactuatable handle 32 away from the palm grip 30. Thus, advancement ofthe stabilization member 50 may be performed by actuating the firsthandle 32 toward the palm grip 30. In some embodiments, a single strokeof the first handle 32 may advance the stabilization member 50 from theinstallation tool 10 a sufficient distance. In other embodiments, aseries of strokes of the first handle 32 toward the palm grip 30 may beperformed, in which the stabilization member 50 moves more distally fromthe installation tool 10 during each of the series of strokes.

The handle portion 12 may include a second trigger or actuatable handle34 which may be used to selectively control one or more of the operativefeatures of the installation tool 10. For instance, the secondactuatable handle 34 may be configured to actuate the driver 46 to expelan anchor 70 from the installation tool 10 when the second handle 34 isactuated. For instance, the second handle 34 may operate and/or release,a lever, valve, cam, rod, spring, or other mechanism of the anchoringmechanism 40 to expel an anchor 70 from the installation tool 10.

The second actuatable handle 34 may be pivotably mounted to the shaft 14such that the second actuatable handle 34 may be actuated relative tothe palm grip 30. Actuation of the second actuatable handle 34 mayinitiate activation of the driver 46 to expel an anchor 70 from theinstallation tool 10. For instance, the second actuatable handle 34 maybe moved toward the palm grip 30 in order to expel an anchor 70 from theinstallation tool 10. Thus, an anchor 70 may be discharged from theinstallation tool 10 with each stroke of the second handle 34 in someinstances.

Additionally, one of the first and/or second actuatable handles 32, 34may be selectively used to selectively control the cutter 54, or theinstallation tool 10 may include a third trigger or actuatable handle tocontrol the cutter 54. For instance, as shown in FIGS. 1 and 3, thefirst actuatable handle 32 may selectively control actuation of thecutter 54.

The installation tool 10 may include a control mechanism 60, such as abutton, switch, toggle, clip, lever, or other feature, which may bemanipulated to selectively control operation of the first actuatablehandle 32. For instance, when the control mechanism 60 is in a firstposition, shown in FIG. 1, actuation of the first handle 32 may advancethe stabilization member 50 from the installation tool 10. When thecontrol mechanism 60 is moved to a second position, shown in FIG. 3,actuation of the first handle 32 may actuate the cutter 54 to sever thestabilization member 50 as discussed above. For instance, in the secondposition shown in FIG. 3, actuation of the first handle 32 may force thecontrol mechanism 60 against a proximal portion of the cutter 54, urgingthe cutter 54 distally to cut the stabilization member 50. However, inthe first position shown in FIG. 1, actuation of the first handle 32 maynot result in actuation of the cutter 54.

It is noted that in some embodiments, the second actuatable handle 32,or an additional handle, may include a control mechanism which mayselectively control actuation of a plurality of operative features ofthe installation tool 10.

FIGS. 4A-4E illustrate an exemplary method of installing a vertebralstabilization system 80 with the installation tool 10 during a medicalprocedure. In some embodiments, the spinal column of a patient may beaccessed in a percutaneous or minimally invasive manner by passing theshaft 14 of the installation tool 10 through an incision 90. In someembodiments, an access cannula, retractor, or other device (not shown)may be inserted into the incision 90 to maintain access to adjacentvertebrae 2 a, 2 b during the medical procedure. In other embodiments,access to the adjacent vertebrae 2 a, 2 b may be maintained directlythrough the incision 90. The vertebrae 2 a, 2 b may be accessed througha posterior approach, an anterior approach, a lateral approach, atranslateral approach, a posterio-lateral approach, or other desiredapproach.

Having gained access to the adjacent vertebrae 2 a, 2 b of the spinalcolumn, the distal end 16 of the installation instrument 10 may be movedadjacent to the first vertebra 2 a and a portion of the stabilizationmember 50 may be advanced out of the distal end 16 of the installationinstrument 10. For instance, the first handle 32 may be actuated to movethe stabilization member 50 distally out of the distal opening 24 of theinstallation tool 10. The ramp 22 may redirect the exposed portion ofthe stabilization member 50 in a direction generally parallel to thespinal column, while the elongate shaft 14 is positioned at an angle,such as an acute angle, to the spinal column.

With the stabilization member 50 positioned at a desired location on thefirst vertebra 2 a, such as the pedicle, vertebral body, spinousprocess, lamina, facet, other posterior bony structures, or other regionof the first vertebra 2 a, the anchoring mechanism 40 may be actuated todrive a first anchor 70 a into the first vertebra 2 a to secure thestabilization member 50 to the first vertebra 2 a. For instance, thesecond handle 34 may be actuated to actuate the driver 46 to push thefirst anchor 70 a from the distal end 16 of the installation tool 10.The first anchor 70 a may be driven into the first vertebra 2 a throughdirect translational movement of the first anchor 70 a, withoutrotational movement such as is necessary in installing a pedicle screw.Thus, the first anchor 70 a may be installed more quickly than the timenecessary to secure a pedicle screw. Note, as discussed above, in someembodiments the first anchor 70 a may be driven into the first vertebra2 a by manually delivering and tamping the first anchor 70 a into placethrough a channel along the shaft 14, or otherwise manually driven intothe first vertebra 2 a.

With the stabilization member 50 secured to the first vertebra 2 a withthe first anchor 70 a, the distal end 16 of the installation tool 10 maybe moved toward the second vertebra 2 b, as shown in FIG. 4B. As theinstallation tool 10 is moved toward the second vertebra 2 b, thestabilization member 50 may be further advanced from the distal end 16of the installation tool 10, extending the stabilization member 50 fromthe first vertebra 2 a to the second vertebra 2 b. For instance, thefirst handle 32 may be actuated as the distal end 16 of the installationtool 10 is moved to the second vertebra 2 b to advance the stabilizationmember 50 along the conduit 20 and out the distal opening 24 of theinstallation tool 10.

Positioned adjacent the second vertebra 2 b, in some instances theinstallation tool 10 may be used to distract the second vertebra 2 bfrom the first vertebra 2 a to alleviate compression of the spinalcolumn and/or attain a desired spacing between the first vertebra 2 aand the second vertebra 2 b. For instance, the prong(s) 26 of theinstallation tool 10 may be engaged with the second vertebra 2 b and theinstallation tool 10 may be manipulated to urge the second vertebra 2 baway from the first vertebra 2 a. In some instances, a separatedistraction tool may be used independently or in conjunction with theinstallation tool 10 to distract the second vertebra 2 b from the firstvertebra 2 a.

With the installation tool 10 adjacent the second vertebra 2 b, thestabilization member 50 may be positioned at a desired location on thesecond vertebra 2 b, such as the pedicle, vertebral body, spinousprocess, lamina, facet, other posterior bony structures, or other regionof the second vertebra 2 b. Having completed distraction of thevertebrae 2 a, 2 b, if any, the anchoring mechanism 40 may then beactuated to drive a second anchor 70 b into the second vertebra 2 b tosecure the stabilization member 50 to the second vertebra 2 b, as shownin FIG. 4C. For instance, the second handle 34 may be actuated toactuate the driver 46 to push the second anchor 70 b from the distal end16 of the installation tool 10. The second anchor 70 b may be driveninto the second vertebra 2 b through direct translational movement ofthe second anchor 70 b, without rotational movement such as is necessaryin installing a pedicle screw. Thus, the second anchor 70 b may beinstalled more quickly than the time necessary to secure a pediclescrew. Note, as discussed above, in some embodiments the second anchor70 b may be driven into the second vertebra 2 b by manually deliveringand tamping the second anchor 70 b into place through a channel alongthe shaft 14, or otherwise manually driven into the second vertebra 2 b.

Once the stabilization member 50 is secured to the second vertebra 2 bwith the second anchor 70 b, any excess portion of the stabilizationmember 50 may be cut away from the portion of the stabilization member50 extending between the first anchor 70 a and the second anchor 70 b.For instance, as shown in FIG. 4D, the cutter 54 may be actuated to cutaway excess portions of the stabilization member 50. This may beachieved, for example, by manipulating the control mechanism 60 suchthat actuation of the first handle 32 moves the cutter 54 distallyallowing the sharpened tip 56 of the cutter 54 to sever thestabilization member 50. As noted above, in other embodiments, thecutter 54 may include jaws which close around the stabilization member50 through actuation of the first handle 32 to sever the stabilizationmember 50. In other embodiments, another cutting device may beintroduced through the incision 90 to cut away excess portions of thestabilization member 50.

FIG. 4E illustrates the installed vertebral stabilization system 80,including the stabilization member 50 and the first and second anchors70 a, 70 b securing the stabilization member 50 to first and secondvertebra 2 a, 2 b, respectively. With the vertebral stabilization system80 installed, movement between the adjacent vertebrae may be limited toa desired amount and/or increased structural integrity between adjacentvertebrae may be attained. For instance, the stabilization member 50 mayprovide tensile strength and/or compressive resistance in order totransfer loading of the spinal column. The flexible nature of thestabilization member 50, however, may allow for some dynamic movement ofthe adjacent vertebrae 2 a, 2 b relative to each other. Once thevertebral stabilization system 80 has been installed, the installationtool 10 may be removed from the patient's body and the incision 90closed to complete procedure.

It is noted that in some instances the installation tool 10 may be usedto install the stabilization member 50, or another stabilization member50, across additional vertebrae in a multi-level stabilization system.For instance if it is desired to install the stabilization member acrossone or more additional vertebrae 2 in a multi-level stabilizationsystem, once the stabilization member 50 has been secured to the secondvertebra 2 b, the installation tool 10 may be moved toward a thirdvertebra 2 c while advancing the stabilization member 50 from the distalend 16 of the installation tool 10 in a similar manner to that describedabove. Once the stabilization member 50 is properly placed on the thirdvertebra 2 c, the anchoring mechanism 40 may be actuated to secure thestabilization member 50 to the third vertebra 2 c with an anchor 70 in asimilar manner to that described above. These steps may be repeated foradditional vertebral levels as desired. Any excess portions of thestabilization member 50 may then be cut away, such as with the cutter54, and then the installation tool 10 may be removed from the patient.

FIGS. 5, 6, 7-7A, 8, 9A-9B and 10A-10B illustrate some possibleconfigurations of the anchor 70 which may be used with the installationtool 10 to secure a stabilization member 50 to vertebrae of a spinalcolumn. FIG. 5 illustrates a staple 170 which may be used to secure astabilization member 50 to vertebrae. The staple 170 includes a firstleg 171, a second leg 172 and a crown 173 extending between the firstleg 171 and the second leg 172. As shown in FIG. 5, in some embodimentsthe first leg 171 may extend parallel to the second leg 172, while inother embodiments the first leg 171 may be divergent from or convergentto the second leg 172. In some embodiments, the crown 173 may have anarcuate shape curving from the first leg 171 to the second leg 172. Suchan arcuate shape may accommodate the shape of a stabilization member 50such that a convex surface of the stabilization member 50 may restagainst or contact a concave surface of the arcuate portion of the crown173. In other embodiments, the crown 173 may extend linearly between thefirst leg 171 and the second leg 172 of the staple 170.

The first leg 171 and/or the second leg 172 may include one or more, ora plurality of barbs 174 which may be embedded in the bone of a vertebrato help secure and retain the staple 170 with the vertebra. Forinstance, the barbs 174 may prevent reverse movement of the legs 171,172 out of the bone. Furthermore, the crown 173 may include a spike 175or other projection configured to protrude into and/or penetrate thestabilization member 50. The spike 175 may help prevent movement of thestabilization member 50 relative to the staple 170 when thestabilization member 50 is secured to the vertebra.

When secured to a vertebra, the stabilization member 50 may extendthrough the central opening of the staple 170 such that the first andsecond legs 171, 172 of the staple 170 straddle the stabilization member50 while the stabilization member 50 is positioned between the crown 173and the vertebra.

FIG. 6 illustrates another staple 270 which may be used to secure astabilization member 50 to vertebrae. The staple 270 includes a firstleg 271, a second leg 272 and a crown 273 extending between the firstleg 271 and the second leg 272. As shown in FIG. 6, in some embodimentsthe first leg 271 may extend parallel to the second leg 272, while inother embodiments the first leg 271 may be divergent from or convergentto the second leg 272. In some embodiments, the crown 273 may have anarcuate shape curving from the first leg 271 to the second leg 272. Suchan arcuate shape may accommodate the shape of a stabilization member 50such that a convex surface of the stabilization member 50 may restagainst or contact a concave surface of the arcuate portion of the crown273. In other embodiments, the crown 273 may extend linearly between thefirst leg 271 and the second leg 272 of the staple 270.

The first leg 271 and/or the second leg 272 may include one or more, ora plurality of barbs 274 which may be embedded in the bone of a vertebrato help secure and retain the staple 270 with the vertebra. Forinstance, the barbs 274 may prevent reverse movement of the legs 271,272 out of the bone. Furthermore, the crown 273 may include a pluralityof projections 275 configured to protrude into and/or penetrate thestabilization member 50. The plurality of projections 275 may extendfrom the crown 273 along a length of the crown 273 of the staple 270.The plurality of projections 275 may help prevent movement of thestabilization member 50 relative to the staple 270 when thestabilization member 50 is secured to the vertebra.

The staple 270 may also include a first ridge 276 on the first leg 271and a second ridge 277 on the second leg 272. The first ridge 276 mayextend toward the second leg 272 and the second ridge 277 may extendtoward the first leg 271. The first and second ridges 276, 277 may beconfigured such that the ridges 276, 277 are located on an under side ofthe stabilization member 50 (i.e., between the stabilization member 50and the vertebra), when the stabilization member 50 is secured to thevertebra with the staple 270. In some instances, the ridges 276, 277 mayhelp force the stabilization member 50 upward into engagement with theprojections 275 protruding from the crown 273 to help retain thestabilization member 50 from moving relative to the staple 270 whensecured to a vertebra. In some instances, the stabilization member 50may be snap fitted into the opening defined between the crown 273 andthe first and second ridges 276, 277 to increase the holding ability ofthe staple 270.

When secured to a vertebra, the stabilization member 50 may extendthrough the central opening of the staple 270 such that the first andsecond legs 271, 272 of the staple 270 straddle the stabilization member50 while the stabilization member 50 is positioned between the crown 273and the vertebra.

Another embodiment of a staple 370 is illustrated in FIGS. 7 and 7A. Thestaple 370 includes a first leg 371, a second leg 372 and a crown 373extending between the first leg 371 and the second leg 372. As shown inFIG. 7, in some embodiments the first leg 371 may extend parallel to thesecond leg 372, while in other embodiments the first leg 371 may bedivergent from or convergent to the second leg 372. In some embodiments,the crown 373 may have an arcuate shape curving from the first leg 371to the second leg 372. Such an arcuate shape may accommodate the shapeof a stabilization member 50 such that a convex surface of thestabilization member 50 may rest against or contact a concave surface ofthe arcuate portion of the crown 373. In other embodiments, the crown373 may extend linearly between the first leg 371 and the second leg 372of the staple 370.

The first leg 371 and/or the second leg 372 may include one or more, ora plurality of barbs 374 which may be embedded in the bone of a vertebrato help secure and retain the staple 370 with the vertebra. Forinstance, the barbs 374 may prevent reverse movement of the legs 371,372 out of the bone.

Furthermore, the crown 373 may include a first rib 377 and a second rib378 extending parallel to the first rib 377 along an inner surface ofthe crown. The first and second ribs 377, 378 may be arcuate, followingthe arcuate curvature of the crown 373. In some embodiments, the crown373 may include a channel 379 between the first rib 377 and the secondrib 378. The first and second ribs 377, 378 may engage the stabilizationmember 50 when the stabilization member 50 is secured to a vertebra withthe staple 370 in order to help prevent movement of the stabilizationmember 50 relative to the staple 270 when the stabilization member 50 issecured to the vertebra.

When secured to a vertebra, the stabilization member 50 may extendthrough the central opening of the staple 370 such that the first andsecond legs 371, 372 of the staple 370 straddle the stabilization member50 while the stabilization member 50 is positioned between the crown 373and the vertebra.

FIG. 8 illustrates a tack 470 which may be used to secure astabilization member 50 to vertebrae. The tack 470 may include a head471 and a shaft 472 extending from the head 471. The shaft 472 mayinclude one or more, or a plurality of barbs 474 which may be embeddedin the bone of a vertebra to help secure and retain the tack 470 withthe vertebra. For instance, the barbs 474 may prevent reverse movementof the tack 470 out of the bone.

When secured to a vertebra, the tack 470 may pierce the stabilizationmember 50 such that the head 471 presses against the stabilizationmember 50 while the shaft 472 extends through the stabilization member50 and into the vertebra. In other embodiments, the stabilization member50 may include a hole through which the shaft 472 of the tack 470extends through.

Another staple 570 which may be used to secure a stabilization member 50to vertebrae is shown in FIGS. 9A-9B. The staple 570 includes a firstleg 571, a second leg 572 and a crown 573 extending between the firstleg 571 and the second leg 572. As shown in FIG. 9A, initially the firstleg 571 may extend parallel to the second leg 572. Furthermore, thecrown 573 may have an arcuate shape curving from the first leg 571 tothe second leg 572. Such an arcuate shape may accommodate the shape of astabilization member 50 such that a convex surface of the stabilizationmember 50 may rest against or contact a concave surface of the arcuateportion of the crown 573. In other embodiments, the crown 573 may extendlinearly between the first leg 571 and the second leg 572 of the staple570.

The first leg 571 and/or the second leg 572 may include one or more, ora plurality of barbs 574 which may be embedded in the bone of a vertebrato help secure and retain the staple 570 with the vertebra. Forinstance, the barbs 574 may prevent reverse movement of the legs 571,572 out of the bone. Furthermore, the crown 573 may include a pluralityof projections 575 configured to protrude into and/or penetrate thestabilization member 50. The plurality of projections 575 may extendlateral toward one another between the first leg 571 and the second leg572. The plurality of projections 575 may help prevent movement of thestabilization member 50 relative to the staple 570 when thestabilization member 50 is secured to the vertebra.

When secured to a vertebra, the stabilization member 50 may extendthrough the central opening of the staple 570 such that the first andsecond legs 571, 572 of the staple 570 straddle the stabilization member50 while the stabilization member 50 is positioned between the crown 573and the vertebra. As shown in FIG. 9B, with the stabilization member 50positioned between the first and second legs 571, 572, the legs 571, 572may be laterally crimped toward one another to secure the stabilizationmember 50 between the legs 571, 572. Crimping of the legs 571, 572 mayforce the projections 575 into engagement with the stabilization member50 such that the projections 575 project into and/or penetrate thestabilization member 50. Crimping the staple 570 may help preventmovement of the stabilization member 50 relative to the staple 570 whenthe stabilization member 50 is secured to the vertebra.

Yet another staple 670 which may be used to secure a stabilizationmember 50 to vertebrae is shown in FIGS. 10A-10B. The staple 670includes a first leg 671, a second leg 672 and a cross member 673extending between the first leg 671 and the second leg 672. As shown inFIG. 10A, in some embodiments the first leg 671 may extend parallel tothe second leg 672, while in other embodiments the first leg 671 may bedivergent from or convergent to the second leg 672.

The staple 670 may also include a first arm 677 and a second arm 678extending from the cross member 673 in a direction generally oppositethat of the first and second legs 671, 672. In embodiments, the firstand second arms 677, 678 may be extensions of the first and second legs671, 672, respectively, extending in opposing directions from the crossmember 673.

As shown in FIG. 10A, initially the staple 670 may have a generallyH-shape in which the first leg 671 extends parallel to the second leg672, and the first arm 677 extends parallel to the second arm 678. Thecross member 673 may have an arcuate shape curving from the first leg671 and first arm 677 to the second leg 672 and second arm 678. Such anarcuate shape may accommodate the shape of a stabilization member 50such that a convex surface of the stabilization member 50 may restagainst or contact a concave surface of the arcuate portion of the crossmember 673. In other embodiments, the cross member 673 may extendlinearly from the first leg 671 and first arm 677 to the second leg 672and second arm 678 of the staple 670.

The first leg 671 and/or the second leg 672 may include one or more, ora plurality of barbs 674 which may be embedded in the bone of a vertebrato help secure and retain the staple 670 with the vertebra. Forinstance, the barbs 674 may prevent reverse movement of the legs 671,672 out of the bone. Furthermore, the first arm 677 and/or the secondarm 678 may include one or more, or a plurality of projections 675configured to protrude into and/or penetrate the stabilization member50. The projections 675 may extend lateral toward one another betweenthe first arm 677 and the second arm 678. The projections 675 may helpprevent movement of the stabilization member 50 relative to the staple670 when the stabilization member 50 is secured to the vertebra.

When secured to a vertebra, the stabilization member 50 may extendthrough the central opening of the staple 670 between the first andsecond arms 677, 678 such that the first and second arms 677, 678 of thestaple 670 straddle the stabilization member 50. Furthermore, the crossmember 673 may be located between the stabilization member 50 and thevertebra. As shown in FIG. 10B, with the stabilization member 50positioned between the first and second arms 677, 678, the arms 677, 678may be crimped around a portion of the stabilization member 50 to securethe stabilization member 50 between the arms 677, 678 and the crossmember 673. Thus, the arms 677, 678 may be crimped into an arcuate shapearound a portion of the perimeter of the stabilization member 50.Crimping of the first and second arms 677, 678 may force the projections675 into engagement with the stabilization member 50 such that theprojections 675 project into and/or penetrate the stabilization member50. Crimping the staple 670 may help prevent movement of thestabilization member 50 relative to the staple 670 when thestabilization member 50 is secured to the vertebra.

FIGS. 11A-11D illustrate some possible configurations of thestabilization member 50 which may provide tensile strength andcompressive resistance. The stabilization member 150 may include anouter layer 152 surrounding an inner core layer 154. The outer layer 152may provide tensile strength while the inner core layer 154 may providecompressive resistance to the stabilization member 150. For instance,the outer layer 152 may be a knit, braided or woven jacket of materialoverlaying the inner core layer 154 which may be placed in tension. Theinner core layer 154 may be formed of a solid material, such as a solidpolymeric material (e.g., an elastomer), which may be placed incompression.

FIG. 11B illustrates another stabilization member 250 which may besubjected to tensile and compressive loading. The stabilization member250 may include an inner core layer 256, an intermediate layer 254surrounding the inner core layer 256, and an outer layer 252 surroundingthe intermediate layer 254. As shown in FIG. 11B, the inner core layer256 may include one or more filaments or strands intermingled (e.g.,twisted, woven, braided, knitted) together. The intermediate layer 254may be formed of a solid material, such as a solid polymeric material(e.g., an elastomer), placed or formed over the inner core layer 256.The outer layer 252 may be a knit, braided or woven jacket of materialoverlaying the intermediate layer 254. The inner core layer 256 and/orthe outer layer 252 may transfer tensile loads through the stabilizationmember 250 and the intermediate layer 254 may transfer compressive loadsthrough the stabilization member 250.

FIG. 11C illustrates another stabilization member 350 which may besubjected to tensile and compressive loading. The stabilization member350 may include an outer layer 352 surrounding an inner core layer 354.The outer layer 352 may provide tensile strength while the inner corelayer 354 may provide compressive resistance to the stabilization member350. For instance, the outer layer 352 may be a knit, braided or wovenjacket of material overlaying the inner core layer 354 which may beplaced in tension. The inner core layer 354 may be formed of a solidmaterial, such as a solid polymeric material (e.g., an elastomer), whichmay be placed in compression. As shown in FIG. 11C, the inner core layer354 may have an oval, or flattened cross section, which may allow for alarger surface area of the stabilization member 350 to be in contactwith the vertebrae of the spinal column, without deformation of thestabilization member 350. The outer layer 352 may transfer tensile loadsthrough the stabilization member 350 and the inner core layer 354 maytransfer compressive loads through the stabilization member 350.

FIG. 11D illustrates yet another stabilization member 450 which may besubjected to tensile and compressive loading. The stabilization member450 may include a first core layer 454 and a second core layer 456extending axially through an outer layer 452. The first core layer 454may be spaced from the second core layer 456 and extending parallel tothe second core layer 456 along the length of the stabilization member450. Each of the first core layer 454 and the second core layer 456 mayinclude one or more filaments or strands intermingled (e.g., twisted,woven, braided, knitted) together. The outer layer 452 may be formed ofa solid material, such as a solid polymeric material (e.g., anelastomer), placed or formed over the first and second inner core layers454, 456. As shown in FIG. 11D, the outer layer 452 may have an oval, orflattened cross section, which may allow for a larger surface area ofthe stabilization member 450 to be in contact with the vertebrae of thespinal column, without deformation of the stabilization member 450.Furthermore, in some instances, an anchor may penetrate the centralportion of the outer layer 452 between the first and second inner corelayers 454, 456 to secure the stabilization member 450 to a vertebra.The first and second inner core layers 454, 456 may transfer tensileloads through the stabilization member 450 and the outer layer 452 maytransfer compressive loads through the stabilization member 450.

In some embodiments, the stabilization member 50 may be a monolithicstructure formed of a single piece of flexible material, includingnatural or synthetic elastomers, thermoplastic elastomers, for example,polyurethane elastomers such as polycarbonate urethane, or otherpolymeric materials. The stabilization member 50 may be molded,extruded, or otherwise formed from a desired material. In such anembodiment, the stabilization member 50 may be able to withstand bothtensile and compressive loads, as desired.

Those skilled in the art will recognize that the present invention maybe manifested in a variety of forms other than the specific embodimentsdescribed and contemplated herein. Accordingly, departure in form anddetail may be made without departing from the scope and spirit of thepresent invention as described in the appended claims.

1-20. (canceled)
 21. A vertebral stabilization installation toolcomprising: a handle; an elongate shaft having a proximal end connectedto the handle, the elongate shaft extending away from the handle along alongitudinal axis of the installation tool, the elongate shaftcomprising: a conduit that directs a stabilization member through theelongate shaft from the proximal end toward a distal end; and a ramplocated at the distal end that receives the stabilizing member from theconduit and discharges the stabilizing member in a direction away fromthe longitudinal axis of the installation tool.
 22. The vertebralstabilization installation tool of claim 21, further comprising: asecond handle pivotably coupled to the elongate shaft and actuatable toadvance the stabilization member from the proximal end toward the distalend.
 23. The vertebral stabilization installation tool of claim 21,further comprising: an anchoring mechanism connected to the distal endof the elongate shaft, the anchoring mechanism configured to dischargean anchor to secure the stabilizing member.
 24. The vertebralstabilization installation tool of claim 23, further comprising: adriver actuatable to discharge the anchor from the installation tool anddrive the anchor into a vertebra.
 25. The vertebral stabilizationinstallation tool of claim 24, further comprising: a second conduitextending from the proximate end of the elongate shaft to the distalend, the second conduit guiding the driver and directing discharge ofthe anchor.
 26. The vertebral stabilization installation tool of claim25, wherein the anchoring member includes a cartridge coupled to thesecond conduit proximate the distal end of the elongate shaft, thecartridge housing a plurality of anchors feedable to the driver.
 27. Thevertebral stabilization installation tool of claim 26, wherein thecartridge comprises a spring that applies a force on the plurality ofanchors to feed anchors to the driver.
 28. The vertebral stabilizationinstallation tool of claim 24, further comprising: a cutter extendingalong the elongate shaft and operable to sever a portion of thestabilization member adjacent to the ramp.
 29. The vertebralstabilization installation tool of claim 28, further comprising: asecond handle pivotably coupled to the elongate shaft and actuatable toadvance the stabilization member from the proximal end toward the distalend; and a control mechanism movable between a first position and asecond position so actuation of the second handle advances thestabilization member when the control mechanism is in the first positionand actuates the cutter when the control mechanism is in the secondposition.
 30. The vertebral stabilization installation tool of claim 24,further comprising: a second handle pivotably coupled to the elongateshaft and actuatable to advance the stabilization member from theproximal end toward the distal end; and a third handle pivotably coupledto the elongate shaft, spaced away from the second handle, andactuatable to actuate the driver.
 31. The vertebral stabilizationinstallation tool of claim 30, further comprising: a control mechanismmovable between a first position and a second position so actuation ofthe second handle performs a first function when the control mechanismis in the first position and a second function when the controlmechanism is in the second position.
 32. A vertebral stabilizationinstallation tool comprising: a first handle; an elongate shaft having aproximal end connected to the first handle, the elongate shaft extendingaway from the first handle and terminating at a distal end, the elongateshaft comprising: a conduit that directs a stabilization member throughthe elongate shaft from the proximal end toward the distal end; and aramp located at the distal end that receives the stabilizing member fromthe conduit and redirects the stabilizing member as the ramp dischargesthe stabilizing member; and a second handle connected to the elongateshaft and spaced away from the first handle, the second handleactuatable to controllably advance the stabilizing member.
 33. Thevertebral stabilization installation tool of claim 32, furthercomprising: an anchoring mechanism connected to the distal end of theelongate shaft, the anchoring mechanism configured to discharge ananchor to secure the stabilizing member.
 34. The vertebral stabilizationinstallation tool of claim 33, further comprising: a driver actuatableto discharge the anchor from the installation tool and drive the anchorinto a vertebra.
 35. The vertebral stabilization installation tool ofclaim 34, further comprising: a second conduit extending from theproximate end of the elongate shaft to the distal end, the secondconduit guiding the driver and directing discharge of the anchor. 36.The vertebral stabilization installation tool of claim 35, wherein theanchoring member includes a cartridge coupled to the second conduitproximate the distal end of the elongate shaft, the cartridge housing aplurality of anchors feedable to the driver.
 37. The vertebralstabilization installation tool of claim 36, wherein the cartridgecomprises a spring that applies a force on the plurality of anchors tofeed anchors to the driver.
 38. The vertebral stabilization installationtool of claim 34, further comprising: a third handle pivotably coupledto the elongate shaft, spaced away from the second handle, andactuatable to actuate the driver.
 39. The vertebral stabilizationinstallation tool of claim 32, further comprising: a cutter extendingalong the elongate shaft and operable to sever a portion of thestabilization member adjacent to the ramp.
 40. The vertebralstabilization installation tool of claim 39, further comprising: acontrol mechanism movable between a first position and a second positionso actuation of the second handle advances the stabilization member whenthe control mechanism is in the first position and operates the cutterwhen the control mechanism is in the second position.